This invention relates to dental radiation imaging systems, and in particular to systems having a removable radiation detector so as to permit varied uses of the detector.
Panoramic and cephalometric dental radiation imaging is used to obtain images of a patient's teeth and jaws. Radiation imaging is essential in providing accurate information in the diagnostic process. Imaging techniques, such as bitewing (interproximal), edentulous (toothless), full mouth series, occlusal, periapical, panoramic techniques, and others, provide information in discovering tooth decay, broken fillings, tumors, occlusal trauma, and other effects that would otherwise be unseen by the eye, whether located inside the teeth, between the teeth, or below the gum line, within the gum tissue. In general, the radiological examinations in dentistry may be classified as intraoral and extraoral, determined by where the radiation sensor is placed with respect to the mouth.
In intraoral radiological examinations, the sensor is placed inside of the mouth, and used to acquire a radiation image of a limited, small region with the greatest possible level of detail. In the extraoral radiological examinations, the sensor is positioned outside of the mouth, and used to acquire a radiation image of a far larger region of the human/animal teeth, jaw, and head. In dentistry, common extraoral imaging is divided into two types. Panoramic radiation imaging shows an area, curved following more or less the mandible shape, of the whole maxillo-facial block. Cephalometric radiation imaging shows a projection, as parallel as possible, of the whole or part of the skull. And three-dimensional techniques have been introduced recently.
Extraoral imaging apparatus employs techniques that aim to move the radiation source, the radiation sensor, or both, in relation to the imaged object, thru a desired trajectory, in such a way as to reveal the anatomic structure of interest and ideally to blur the artifacts from non-related radio-opaque structures, such as bones, even though the radiation energy has also been obstructed by those structures. The goal is to produce a radiation image that meets quality criteria, such as showing undistorted anatomic shapes (constant size and the same magnification in both horizontal and vertical direction, orthogonally of the radiation beam) with uniform contrast and enough resolution to reveal the smallest details of interest.
For example, the general Orthopantomogram (also referred to as OPG, panorex, or pano) employs a rotation technique where the center of rotation is moved during the image acquisition in order to reveal the upper and lower jaws (including teeth, bone structure beneath the teeth and the temporomandibular joint (TMJ)) on the produced two-dimensional view. In addition, the cephalometric imaging attachment employs combination of linear and rotation movement, but in order to show a projection, as parallel as possible, of the whole skull.
The first Orthopantomogram device was developed in 1951, and the first manufacturing of such devices was begun in 1964 by Instrumentarium. Since than, companies such as Planmeca, Carestream Health (formerly Kodak), Gendex, Instrumentarium Dental, Sirona, Sorodex, and others manufacture various devices for panoramic and cephalometric radiation imaging. Many extraoral radiation devices, such as the Planmeca ProOne™, Kodak 8000, Gendex Orthoralix™ 8500 DDE, and the Sirona Orthophos™ 3 DS, do not have cephalometric capabilities. Others, such as the Kodak 9000C, provide cephalometric capabilities, but do not have a transferable sensor.
Many dental and surgical offices require both types of imaging systems, and offices requiring both types of imaging systems had been required to purchase both systems. The radiation sensors for panoramic and cephalometric imaging systems are very costly components, and thus greatly increase the overall cost of the systems. A sensor which is transferable between a panoramic and cephalometric system would thus provide a very advantageous cost savings to a user of both systems. A third group of devices, such as Planmeca ProMax™, Gendex Orthoralix™ 9200 AEC, Instrumentarium Dental Orthoceph™ OC200 D, and Sirona Orthophos™ XG, do have cephalometric capabilities and a transferable sensor. Those systems, however, employ connection systems that are complicated, less reliable, and/or expensive.
Further, most of the commonly used connectors in those systems have limited durability, on the order of 500 insertions. A very few connectors could reach 10,000 insertions. This durability sometimes is not enough for the long term usage of certain extraoral X-Ray devices, especially because of the usual long lifespan of more than ten years. Thus, most of the sensors on the market employ custom connectors with spring-loaded contacts to provide the needed maximum durability and reliability, as well as low resistance and capacitance for high-speed data transfer. That choice, however, adds cost to the sensor, and limits the sensor connector only to the essential data signals and power lines.
The present invention relates to improvements to the apparatus described above and to solutions to some of the problems raised or not solved thereby.